Agriculture and, more especially, horticulture pertains to the science and art of growing fruits, vegetables, flowers, or ornamental plants. A large portion of the world's food supply comes from the endeavors of those engaged in horticulture. However, many factors are forcing changes in the methods used by farmers and others engaged in horticulture to produce edible plants. In many areas of the world, land is rapidly being diverted from agricultural purposes to other uses as exemplified by the urbanization of the planet. In some predominantly agricultural areas (e.g., the central valley of California in the United States) water is becoming scarce. Global warming is changing the location and method for growing certain crops. Changes in pests, including the emergence of resistant strains of pests, further stresses the agricultural system. Soil in certain areas has become depleted due to improper crop management over a long period. Acid rain caused by environmental pollution threatens still other crops in some parts of the world. The net result is that farmers using traditional methods have become increasingly ineffective in producing sufficient, cost effective harvests of many crops.
Some of the aforementioned problems have been dealt with. For example, in the central valley of California, an extensive water distribution infrastructure has been built to provide irrigation to crops being grown there. However, the changing environment threatens the very source of the distributed water. Tougher environmental pollution laws are eventually expected to reduce acid rain and the effects of other similar problems in areas progressive enough to recognize the threat of such pollution.
To solve some of these problems, attempts have been made to change the method of growing plants. In the field of container horticulture, different systems have been developed to provide an integrated approach to plant growth. These systems and methods include the use of hydroculture, hydroponics, artificial growing media, natural potting soil, and others known to those of skill in the horticultural arts.
Hydroculture systems immerse the entire root mass of a plant in stagnant nutrient water. While some plants are able to adapt to such conditions, many cannot.
Hydroponic systems also place the entire root mass of a plant in liquid, but the liquid is typically flowing nutrient water and the system utilizes a pump irrigation system. Many hydroponic systems supply nutrient-bearing water to the plants' roots only intermittently. Again, while some plants thrive in hydroponic environments, many do not. From a commercial point of view, hydroponics is limited to a relatively small percentage of edible plants.
Artificial growing media are known to be viable alternatives to conventional soil. Artificial growing media are particularly useful in growing plants, (e.g., orchids and other epiphyte plants) which have evolved their root system primarily for anchoring purposes in media other than soil. Artificial growing media includes mixtures of bark, peat moss, Spanish moss, sphagnum moss, fertilizer, vermiculite, etc.
Systems of containers using natural soil are known and used as they have proven themselves able to sustain the life of most plants, at least over a predetermined period. Several improvements for such natural soil containers have been suggested and, in some cases, implemented. For example, self-watering devices such as wicks or other bottom reservoirs have been suggested.
While container growing systems of the prior art may provide the roots with direct contact with soil particles and microorganisms, the water reservoir is generally not large enough or available enough for the growing needs of all plants.
Another fundamental limitation of prior art container growing systems relates to the fact that the roots of some plants cultivated in these containers become cramped, typically inside a compact ball of soil. Roots cannot expand outside of the ball of soil without being damaged as typically they escape only through drainage holes or other similar orifices in the container itself. Growing roots that reach the bottom of such plant containers tend to grow in a spiral pattern. Such growth patterns have been shown to waste growth resources of the plant. The roots, therefore, become engaged in a vicious cycle of unnecessary growth in order to find the necessary space for water seeking and uptake. This provokes the suffocation of root tissue, the complete arrest of growth by the plant, and the start of dormancy. Persons familiar with the art of plant husbandry recognize the symptoms of a “root bound” plant. They know that it eventually becomes time to transplant the plant into a larger container (e.g., pot). Left root bound, many plants lose their leaves and, eventually, die.